Artillery firing system

ABSTRACT

A recoil buffering apparatus for use with an artillery gun of the type comprising a breech assembly ( 15 ) connected to a barrel ( 12 ), the breech assembly ( 15 ) having a firing mechanism for firing a projectile through an open end of the barrel ( 12 ). The recoil buffering apparatus comprises a recoil buffering means adapted to be fixed to the barrel ( 12 ) and movable therewith during recoil action of the barrel ( 12 ) caused by firing of the projectile, and a support means associated with the recoil buffering means for supporting the recoil buffering means and thereby supporting the barrel ( 12 ) and breech assembly ( 15 ) through the recoil buffering means. An elevating apparatus and a traversing apparatus for an artillery gun are also described. The artillery gun can also be provided with a muzzle brake ( 11 ).

FIELD OF INVENTION

[0001] This invention relates to a platform or vehicle-mounted artilleryfiring system and in particular to a platform or vehicle-mounted mortarsystem and improvements in relation thereto.

BACKGROUND AND PRIOR ART

[0002] Traditionally, a mortar system was an infantry and commandoweapon that was designed for man-packing. It had to be broken down intoa few sub-assemblies to resolve the weight constraint necessitated byman-packing. Therefore, to set up the mortar system for firing will takeat least a few minutes. However, mortar systems have now been mounted onvarious vehicles to meet the quick response required in performinghit-and-run missions demanded in modern warfare.

[0003] The traditional mortar system consists of a barrel and breechassembly, bipod assembly and a base-plate. The breech piece has aspherical joint with the base-plate sitting on the ground. The bipodassembly is used for supporting the barrel and for fine adjustment ofits elevation and travel. The gas pressure acting on the breech and thereaction force generated during firing, which are subsequentlytransmitted onto the structure (base-plate) is very high. It could be ashigh as 150,000 kPa, but it is not a problem for a solid structure suchas a base-plate that sits on the ground and acts as a natural damper.

[0004] When the mortar system is platform-mounted (in particular when itis mounted on a vehicle), most system integrators currently use thetraditional mortar system and focus on designing the structure towithstand the firing force. This will result in heavy structuralreinforcement/modification of the mounting platform (vehicle). Thedamming adapter has been developed by some system integrators as aninterface between the mortar and the platform (vehicle) which is able toreduce the firing force to about 40%. However, even with a 60% reduction(60,000 kPa) of the firing force, it is still very large and requires aheavy structure to withstand it. The suspension system also requiresreinforcement if the platform (vehicle) is designed to fire on it.

[0005] The following problems have been borne in mind when solving thedeficiencies, such as lack of recoil buffering and accuracy of themortar systems of the prior art, and the lack of manoeuverability of thewhole vehicle.

[0006] Recoil Mechanism

[0007] The recoil buffer mechanism is the most essential part of the gunsystem. The traditional mortar system is designed for man-packing andtherefore its weight must be relatively lighter to allow portability.Thus the recoil mechanism has never been considered for use in themortar system. However, when the mortar system is platform-mounted(vehicle-mounted), the recoil forces become more critical compared tothe weight of the individual sub-assembly. Hence, some systemintegrators have incorporated the recoil mechanism to absorb the highrecoil force, but this mechanism may not be efficient as the recoilingmass is too low to absorb the firing energy effectively and subsequentlyconvert it to the recoil braking force.

[0008] Cradle Design of Conventional Gun Systems

[0009] “O”-cradle designs, “U”-cradle designs and a combination of bothare the three most common cradle designs in gun systems that are usedfor the support and guidance of the recoiling mass during firing.

[0010] The “O” cradle design is the first-generation gun cradle design.It has two bushes at both ends of the cradle to support and allow thebarrel to slide on its outer cylindrical surface when recoiling duringfiring. It is the simplest in construction and the most commonly-useddesign. The big and long cylindrical sliding surface on the barrelcarries an excessive amount of weight. On the other hand, there areminimum number of parts attached on the recoiling mass, which reducesthe effectiveness of the buffering of the recoil.

[0011] The “U” cradle design is the second-generation gun cradle design.The “T” shaped slot on the cradle is used to support and guide thebarrel while recoiling during firing. Two brackets are attached onto thebarrel (or one on the barrel and one on the breech) as a bridge betweenthe barrel and cradle. The external profile of the barrel can beoptimized to achieve the design strength (gas pressure distanceprofile). Hence, there will be significant weight reduction on thebarrel. The recoil cylinder can be attached together with the barrel toincrease the recoiling mass to reduce the recoiling force. However, thecradle is complex in both design and manufacturing.

[0012] The “O” and “U” combination cradle design takes advantage of thebenefits of both the above designs. Its front support is an “O” cradledesign and its rear side is a “T” cradle design. The cylindrical surfaceof the barrel on its centre portion is used for front sliding and onlyone bracket is attached onto either the barrel or on the breech as therear support. The barrel external profile is very close to an optimizeddesign and it saves one bracket. The cradle is, however, complex in bothdesign and manufacturing. Regardless of all the three types of cradledesign, the minimum length of the cradle will be two×supportlength+recoiling length+safety allowance.

[0013] Muzzle Brake

[0014] To-date, the muzzle brake has not been adopted onto any mortarsystem. The traditional mortar system is designed to be man-packed. Itsweight is very critical. Therefore, the muzzle brake has never beenconsidered for the mortar system.

[0015] The bomb muzzle velocity is very much slower than the gas flowwhen it leaves the barrel. The bomb will be unstable because of gasturbulence at the muzzle. Trying to re-stabilize the flight path of thebomb during flight will result in the bomb losing its kinetic energy andaccuracy.

[0016] Elevating and Traversing Mechanism

[0017] The most common elevating mechanisms used in gun design are thearc and pinion gear design, the single actuator at the centre, or twoactuators installed on both sides of the elevating mass in parallel. Thebase width of these mechanisms is quite small.

[0018] The arc and pinion gear or linear actuator are most commonly usedfor the traversing mechanism. In the arc and pinion mechanism, backlash(clearances) in the gear trains is essential to ensure the smoothrunning of the mechanism. The acceptable backlash in the traversingmechanism for accurate gun laying demand high precision and costlycomponents. Alternatively, complex anti-backlash mechanisms are normallyemployed to resolve the problem. Another disadvantage is that the gearteeth have friction due to their relative movements and are prone towear and tear since it is very difficult to protect against dust anddirt in its operating environment. The uneven wear and tear will causemalfunction of the anti-backlash mechanism after prolonged usage.

[0019] The linear actuator is only used in traverse mechanisms having asmaller arc of traverse. Furthermore, it has a non-linear (cosine error)correlation movement between the linear actuator and the rotatingaction. This will complicate the control system for a closed-loop powerdrive system.

[0020] The invention herein seeks to overcome most of the disadvantagesin the prior art mentioned above.

SUMMARY OF THE INVENTION

[0021] An objective of the invention is to reduce the recoil force thatacts on the structure of the artillery firing platform by up to 80%. Wehave found that providing a tetrahedron shape for the arrangement of theelevating cylinder avoids causing each member to suffer excessivebending force and the stable shape allows the barrel to move in oneplane or in one direction. Therefore, the improved system can be mountedon a much lower class of platform or vehicle (eg. from a 30-tonnevehicle to a 10-tonne vehicle). This is achieved by optimizing thesystem design and incorporating the recoil buffer, muzzle brake andmaximizing the recoil mass. Such a design also increases the range andimproves the accuracy of the bomb.

[0022] Further, another objective is to simplify the design andincreasing the efficiency of the cradle and traversing mechanism for theartillery firing system. We have found that, if the recoil cylinder isanchored directly to the saddle, the cradle becomes lighter when therecoil force bypasses the cradle. The external surface of the recoilcylinder is used as a sliding and guiding surface to allow the recoilingmass to slide during recoil when firing the gun. Furthermore, in atraversing mechanism, a steel cable is used in place of gears so thatthere is zero backlash.

[0023] Another objective of the invention is to improve the safety ofthe crew by reducing the blast (overpressure) at the gun crew area.

[0024] According to one aspect of the invention there is provided arecoil buffering apparatus for use with an artillery gun of the typecomprising a breech assembly connected to a barrel, the breech assemblyhaving a firing mechanism for firing a projectile through an open end ofthe barrel, the recoil buffering apparatus comprising a recoil bufferingmeans adapted to be fixed to the barrel and movable therewith duringrecoil action of the barrel caused by firing of the projectile, and asupport means associated with the recoil buffering means for supportingthe recoil buffering means and thereby supporting the barrel and breechassembly through the recoil buffering means.

[0025] Preferably, the support means includes a cradle, and the recoilbuffering means is slidable along the cradle. Preferably also, thesupport means includes a support platform, and one end of the recoilbuffering means is directly secured to the support platform. In thepreferred construction, the recoil buffering means is pivotally securedto the support platform.

[0026] It is preferred that the recoil buffering means comprises abuffering cylinder having a piston attached thereto the piston beingslidable relative to the buffering cylinder, and the piston andbuffering cylinder being arranged so that sliding movement therebetweenprovides the buffering action.

[0027] It is desirable that one end of the buffering cylinder is adaptedto be secured to the barrel by means of a yoke, and the other end of thebuffering cylinder is provided with a guide surface adapted to maintainthe barrel and the buffering cylinder in proper alignment.

[0028] Preferably, the barrel and the buffering cylinder havesubstantially parallel longitudinal axes. The piston of the recoilbuffering means is preferably pivotally secured to the support platform,and the buffering cylinder of the recoil buffering means is preferablyslidable along the cradle.

[0029] It is preferred that the cradle includes an aperture within whichat least a part of the buffering cylinder is slidably received, and thatsaid aperture includes an inner surface which acts to support thebuffering cylinder.

[0030] In a preferred embodiment, the recoil buffering means comprisestwo of said buffering cylinders and pistons, and the cradle includes twoof said apertures, each aperture receiving a respective one of saidbuffering cylinders. It will be appreciated that it is possible toprovide more than two of said buffering cylinders pistons.

[0031] The support means is arranged such that, in use, there is nodirect connection between the support means and the barrel or the breechassembly. Thus, the weight of the barrel and breach assembly are allsupported by the support means through the recoil buffering means.

[0032] According to another aspect of the invention there is provided anelevating apparatus for an artillery gun of the type comprising a breechassembly connected to a barrel, the breech assembly having a firingmechanism for firing a projectile through an open end of the barrel, theelevating apparatus comprising a support means adapted to support thebarrel and breech assembly and an elevating mechanism for raising andlowering the barrel wherein the elevating mechanism includes a pistonand cylinder which are arranged such that relative movement between thepiston and cylinder causes the barrel to be raised or lowered.

[0033] Preferably the piston and cylinder are secured to the supportmeans, and preferably there are two of said pistons and cylinders.

[0034] The support means preferably includes a cradle adapted to supportthe barrel directly or indirectly, and at least one support membersecured at one end to the cradle and at the other end to a supportplatform. The piston and cylinder may be secured to the cradle so thatthey can provide support for the barrel and the breech assembly.

[0035] A connecting member is desirably connected between the supportplatform and each of said pistons and cylinders, and a cross-connectingmember is desirably connected between said pistons and/or between eachof said cylinders.

[0036] In the preferred embodiment, the arrangement of the pistons andcylinders, the connecting members, the cross-connecting member and theor each support member is substantially tetrahedral.

[0037] According to another aspect of the invention there is provided atraversing apparatus for an artillery gun comprising a breech assemblyconnected to a barrel, the breech assembly having a firing mechanism forfiring a projectile through an open end of the barrel, the traversingapparatus comprising; a support platform which is adapted to support thebarrel and breech assembly in such a manner that said barrel and breechassembly may rotate relative to the support platform in order to imparta traversing motion to the barrel and breach assembly, the supportplatform including an arcuate guide member having support means adaptedto support the barrel and breech assembly so that the support meansfollows the guide member during said traversing motion of the barrel andbreech assembly; and drive means secured to the support means andadapted to drive movement of the support means along the guide member tocause said traversing motion, wherein the drive means comprises a drivewheel and a drive cable wrapped around the drive means or in connectiontherewith, the drive cable being substantially fixed relative to theguide member so that rotation of the drive wheel causes the drive wheeland the support means to be driven along the guide member.

[0038] The drive cable preferably sits in a recess provided in the drivewheel. The recess in the drive wheel preferably extends around the drivewheel in a substantially helical fashion. The drive cable may extend atleast partly around the guide member. It is desirable that tensioningmeans is provided to maintain the drive cable in tension.

[0039] The support means may include at least one support member adaptedto support the barrel and the breech assembly. Preferably, the or eachsupport member includes a mechanism for adjusting the elevation of thebarrel. Most preferably; there are two support members.

[0040] In a preferred embodiment, the guide member is provided with aT-shaped recess, and the support means is provided with a formationadapted to engage the recess thereby guiding movement of the supportmeans along the guide member.

[0041] According to another aspect of the invention there is provided anelevating apparatus for an artillery gun of the type comprising a breechassembly connected to a barrel, the breech assembly having a firingmechanism for firing a projectile through an open end of the barrel, theelevating apparatus comprising three base members disposed in asubstantially triangular arrangement, and three support members arrangedto support the artillery gun, wherein at least one of the supportmembers is extendible to vary the elevation of the artillery gun, andwherein the base members and the support members are disposed in asubstantially tetrahedral arrangement.

[0042] Preferably, two of the support members are extendible. Preferablyalso, the or each extendible support member comprises a piston andcylinder arrangement.

[0043] The elevating apparatus according to this aspect of the inventionmay also be provided with features of the elevating apparatus describedabove.

[0044] According to another aspect of the invention there is provided anartillery gun comprising a breech assembly connected to a barrel, thebreech assembly having a firing mechanism for firing a projectilethrough an open end of the barrel, wherein the barrel includes a muzzlebrake through which projectile propellant gas can escape from thebarrel.

[0045] The muzzle brake is disposed adjacent the open end of the barrel.Preferably, the muzzle brake comprises a plurality of apertures providedadjacent to the open end of the barrel.

[0046] Any combination of the recoil buffering apparatus, the elevatingapparatus and the traversing apparatus may be used in the artillery gun.

[0047] According to another aspect of the invention there is provided anartillery gun comprising a breech assembly connected to a barrel, thebreech assembly having a firing mechanism for firing a projectilethrough an open end of the barrel, and further comprising a recoilbuffering apparatus as described above, an elevating apparatus asdescribed above, and/or a traversing apparatus as described above.

[0048] The artillery gun according to the invention is preferablyplatform or vehicle mounted.

[0049] As used herein the expression “artillery gun” means guns,cannons, howitzers, mortars and the like, which have a calibre of atleast 40 mm, preferably above 50 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings illustrates the preferred embodiment of theinvention relating to its use in a mortar system.

[0051]FIG. 1 is an isometric view of the mortar system together with anenlarged view of the traversing mechanism.

[0052]FIG. 2 is a side view of the mortar system illustrated in FIG. 1.

[0053]FIG. 3 is a plan view of the mortar system illustrated in FIG. 1.

[0054]FIG. 4 is a front view of the mortar system illustrated in FIG. 1.

[0055]FIG. 5 is a side view of a mortar bomb leaving the barrel of aconventional mortar gun illustrating the effect of muzzle disturbance onthe mortar bomb.

[0056]FIG. 6 illustrates a mortar bomb leaving the barrel of a mortargun fitted with a muzzle brake according to the present invention.

[0057]FIG. 7 shows an end view of the muzzle brake according to thepresent invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0058]FIG. 1 is an isometric view of the mortar system according to thepreferred embodiment of this invention. FIG. 1 should be read with FIGS.2, 3 and 4 which illustrate the side, plan and front views of the mortarsystem respectively. The mortar system consists of the recoiling mass10, elevating mass 20, traversing mass 30 and track assembly 50.

[0059] Recoiling Mass

[0060] The recoiling mass 10 consists of a muzzle brake 11, barrel 12,breech 15, yoke 13, recoil buffer cylinder 17 and lock nuts.

[0061] A muzzle brake 11 with a pepper-port design is located at thefront end of the barrel. It could either be integrated into the barrel12 (mono-block) or detachable for ease of production. The breech 15 withthe firing mechanism (not shown) and firing lever 16 are attached at theother end of the barrel to form the chamber for firing. The barrel 12 issupported by the yoke 13 and is secured by the lock-nut yoke 14.

[0062] The two recoil buffer cylinders 17 are attached to the yoke 13and fastened to it by the lock-nut recoil buffer 18. The recoil bufferpiston rods 23 are pivoted to the trunnion 32 on the saddle 31. Theguiding surface (C) on the outer surface of the recoil buffer cylinders17 will guide the barrel 10 and ensure that the recoil buffer cylindersand barrel are parallel. During the recoiling motion, the wholerecoiling mass 10 is sliding relative to the cradle 21 on the outersurface (A) of the recoil buffer cylinders 17 and outer surface (B) ofthe recoil buffer piston rods 23.

[0063] The recoil buffer has a hydra-pneumatic type design, in that thebuffer and recuperating functions are integrated. It is optimized forthe particular recoiling mass 10 for firing the maximum charge of theparticular bomb. It is designed to convert the impulsive force that isgenerated by the gas pressure to kinetic energy and subsequently todischarge it as a braking force evenly throughout the whole length ofthe recoiling stroke. The recoiling mass 10 will be pushed back to itsoriginal position after the kinetic energy has been completelydischarged by the energy stored in the recoil buffer cylinders 17.

[0064] The invention significantly simplifies the cradle design andreduces the recoiling force by maximizing the recoil mass 10. Theinvention simplifies the cradle design by using the recoil slidingsurface (A) of the recoil buffer cylinder 17 and the piston rods 23 thatserve as supports and guides for the whole recoiling mass. The length ofthe cradle 21 is very much shortened (it has only one support length)and it is supported on the outer surface of the recoil buffer cylinder17 instead of the two supporting points on the barrel, so that thecradle does not experience any recoiling force. The two recoil buffercylinders 17 are mounted together with the barrel 12.

[0065] During firing, the gas pressure generated in the barrel 12 thatacts on the breech end will be transformed to kinetic energy byaccelerating the recoiling mass. The braking force will be generated bythe recoil buffering action and transmitted to the two recoil buffercylinders 17 through the yoke 13. The two recoil buffer cylinders 17 areparallel with the barrel and recoil buffer piston rods 23 are pivoted tothe trunnion 32 on the saddle 31 directly. The invention reduces therecoil force by attaching the two recoil buffer cylinders 17 togetherwith the barrel 12 to maximize the recoiling mass and reducing theweight of the cradle by anchoring the piston rods 23 of the recoilbuffer cylinder 17 to the saddle 31 directly. Therefore, the recoilforce is directed to the saddle 31 and the cradle 21 will not sufferfrom any recoil force. Hence, the function of the cradle 21 will only beto support and guide the recoiling mass 10, and the structural strengthof the cradle can be substantially reduced.

[0066] Muzzle Brake

[0067] The mortar system incorporates a muzzle brake 11 onto the barrelof the artillery gun to reduce the recoiling force and blast(overpressure at the gun crew area). It also increases the range andimproves the accuracy of the bomb.

[0068]FIG. 5 is a side view of a mortar bomb 60 leaving the barrel 70 ofa conventional mortar gun illustrating the effect of muzzle disturbanceon the mortar bomb 60. There is muzzle disturbance because thepropellant gases escape through the opening of the barrel 70 as the bomb60 leaves the opening of the barrel 70. The tilting of the bomb 60caused by the disturbance is quite significant. As a result of themuzzle disturbance, the accuracy of the bomb is much reduced.

[0069]FIG. 6 illustrates a mortar bomb 60 leaving the barrel 12 of amortar gun fitted with a muzzle brake 11 according to the presentinvention. The muzzle brake 11 includes a plurality of portholes toallow the gases to escape from the barrel 12 through the portholesinstead of through the mouth of the barrel 12. The invention allowssignificant amount of gases to escape through the portholes before thebomb leaves the barrel muzzle. Therefore, the gas pressure at the muzzle11 when the bomb 60 leaves the barrel 12 will be significantly reduced,thereby reducing muzzle disturbance. Consequently, the bomb 60 willreach steady-flight very much earlier, which will increase the range andimprove the accuracy of the bomb 60.

[0070] The invention also reduces blast (overpressure at the gun crewarea) as the release of the high-pressure gases has been spread over alonger period of time. It further reduces the recoiling force because ofthe muzzle brake efficiency. The change in direction of thehigh-pressure gas flow that acts on the muzzle brake 11 will reduce therecoil force, unlike in the conventional mortar system without themuzzle brake.

[0071] Elevating Mass

[0072] The elevating mass 20 consists of the cradle 21 and the whole ofthe recoiling mass 10.

[0073] The cradle 21 is designed to support and guide the wholerecoiling mass 10 on the outer surface A of the two recoil buffercylinders 17. The cradle 21 is connected by the cradle connecting tube22 and pivoted at the trunnion 32 on the saddle 31. The bottom of thecradle 21 is connected to the elevating cylinders 40 to vary theelevation of the whole elevating mass 20.

[0074] Elevating Mechanism

[0075] FIGS. 1 to 4 also illustrate the design of the elevating andtraversing mechanism. The cradle 21 of the mortar system is mounted ontwo elevating cylinders 40. Two saddle connecting tubes 33 and across-connecting tube 36 form a base triangle. The cradle connectingtubes 22, saddle connecting tubes 33 and elevating cylinders 40 form twoside triangles. The elevating cylinders 40 are sited on the left frontsupport 34 and right front support 35 and both are connected to thecradle 21 for varying the elevation of the whole elevating mass 20. Theelevating mechanism of the two elevating cylinders 40 could be hydraulicor mechanical screw types. However, regardless of either type of design,the two elevating cylinders 40 have to be linked for synchronousmovement.

[0076] The two elevating cylinders 40 and the cross-connecting tube 36form a front triangle. The four triangles mentioned forms a tetrahedronshape. This is the most stable geometry since the base width of themechanism has been significantly increased. This geometry alsoeliminates any bending moment that acts on the structural members.Hence, the structural strength and weight of the elevating mass designis substantially reduced. The invention thus reduces the number ofmoving joints of the whole elevating mechanism and also simplifies thedesign.

[0077] Traversing Mass

[0078] The traversing mass 30 consists of a saddle 31, two connectingtubes 33, left front support 34, right front support 35 with traversinggear housing 37, cross connecting tube 36, two elevating cylinders 40and the whole of the elevating mass 20.

[0079] The saddle 31 is sited in the centre of the track assembly 50 andis rotatable. The left front support 34 and right front support 35 haveradii “T” slots. Both front supports 34,35 ride on the track of thetrack assembly 50 which is concentric with the centre and allows bothfront supports 34,35 to slide on it. The saddle 31 and front supports34,35 are all connected by two saddle connecting tubes 33 and crossconnecting tube 36 to form a triangular base.

[0080] The elevating cylinder 40 is sited on the left front support 34and right front support 35 and both front supports 34,35 are connectedto the cradle 21 to vary the elevation of the whole elevating mass 20.

[0081] Traversing Mechanism

[0082] The traversing mechanism consists of a three base connectingtubes 33,36 connecting the left front support 34, right front support 35and the saddle 31. The saddle 31 is sited in the centre of the trackassembly 50 and is rotatable around a vertical axis. The left frontsupport 34 and the right front support 35 have radii “T” slots. Theyride on the track of the track assembly 50 which is concentric with thecentre and allows the left front support 34 and the right front support35 to slide on it. The saddle 31 and front supports 34 & 35 areconnected by two saddle connecting tubes 33 and cross-connecting tube 36to form a triangular base. The assembly allows the traversing mass 30 torotate along the track assembly 50. There is a pinion 38 engaging thestructure to the track assembly 50 to permit lateral traverse of thestructure.

[0083] The invention differs from the conventional arc and pinion as thegear teeth is replaced with a steel cable 39. The steel cable 39 restson the plain cylindrical surface of the track assembly 50 with one endfixed. It wraps around the pinion 38 while the other end is tensioned bya spring (not shown). The steel cable 39 sits in the semi-circularspiral groove on the pinion 38. The pinion 38 holds its position firmlyas it is squeezed by the tension in the steel cable 39. The semicircularspiral groove on the pinion increases the contact surface between thesteel cable 39 and the pinion 38. It also improves the gripping powerand prevents deformation of the steel cable.

[0084] The traversing gear housing 37 is attached to the right frontsupport 35 as an integrated block. It houses the bearings, which supportthe pinion 38. The pinion's driving mechanism could be a worm and wormgear, which is a very common design, and can be manual or power driven.

[0085] The traversing movement is generated when the pinion 38 isrotated in similar fashion to a gear's arc and pinion action. Therotating action of the pinion 38 winds the steel cable 39 from one sideas well as concurrently unwinding it on the opposite side. Therefore, adifferential tension in the steel cable 39 will be generated and willsubsequently move the traversing mass 30.

[0086] Unlike the gear teeth in a conventional arc and pinion design,the invention does not have a relative movement in between the steelcable 39 and the pinion 38. Therefore, there is zero backlash in thetraversing mechanism. In addition, dust and dirt trapped in the steelcable and the pinion will not affect its functionality. The inventionalso eliminates the problem of malfunctioning in extreme temperaturescaused by the thermal expansion of the material in the conventional arcand pinion design as whatever changes in the size of material caused bya change in temperature will be automatically compensated by the tensionin the steel cable spring (not shown). Therefore, it becomes anenvironmentally full-proof system.

[0087] The invention is also very much simplified, lighter in weight andsignificantly allows larger tolerance in the production of thecomponents.

[0088] The invention described herein is susceptible to variations,modifications and/or additions other than those specifically describedand it is to be understood that the invention includes all suchvariations, modifications and/or additions which fall within the spiritand scope of the above description. Although the preferred embodiment ofthe invention mentioned above relates to a mortar firing system, theinvention may also be suitable for other types of artillery systems.

1. A recoil buffering apparatus for use with an artillery gun of thetype comprising a breech assembly (15) connected to a barrel (12), thebreech assembly (15) having a firing mechanism for firing a projectile(60) through an open end of the barrel (12), the recoil bufferingapparatus comprising a recoil buffering means adapted to be integratedor otherwise secured to the barrel (12) and movable therewith duringrecoil action of the barrel (12) caused by firing of the projectile(60), and a support means associated with the recoil buffering means forsupporting the recoil buffering means and thereby supporting the barrel(12) and breech assembly (15) through the recoil buffering means. 2.Apparatus according to claim 1 wherein the support means includes acradle (21), and the recoil buffering means is slidable along the cradle(21).
 3. Apparatus according to claim 1 or 2, wherein the support meansincludes a support platform (31), and one end of the recoil bufferingmeans is directly secured to the support platform (31).
 4. Apparatusaccording to claim 1, 2 or 3, wherein the recoil buffering meanscomprises a buffering cylinder (17) having a piston (23) attachedthereto, the piston (23) being slidable relative to the bufferingcylinder (17)′ and the piston (23) and buffering cylinder (17) beingarranged so that sliding movement therebetween provides the bufferingaction.
 5. Apparatus according to claim 4, wherein one end of thebuffering cylinder (17) is adapted to be secured to the barrel (12) bymeans of a yoke (13), and the other end of the buffering cylinder isprovided with a guide surface (C) adapted to maintain the barrel (12)and the buffering cylinder (17) in proper alignment.
 6. Apparatusaccording to claim 5, wherein, in use, the barrel (12) and the bufferingcylinder (17) have substantially parallel longitudinal axes. 7.Apparatus according to claim 4, 5, or 6, when dependent upon claim 3,wherein the piston (23) of the recoil buffering means is pivotallysecured to the support platform (31).
 8. Apparatus according to claim 4,5, 6 or 7, when dependent upon claim 2, wherein the buffering cylinder(17) of the recoil buffering means is slidable along the cradle (21) 9.Apparatus according to claim 8, wherein the cradle (21) includes anaperture within which at least a part of the buffering cylinder (17) isslidably received, and said aperture includes an inner surface whichacts to support the buffering cylinder (17).
 10. Apparatus according toany one of claims 4 to 9, wherein the recoil buffering means comprisestwo of said buffering cylinders (17) and pistons (23).
 11. Apparatusaccording to claim 10, when dependent upon claim 9, wherein the cradle(21 ) includes two of said apertures, each aperture receiving arespective one of said buffering cylinders (17).
 12. Apparatus accordingto any preceding claim, wherein the support means is arranged such that,in use, there is no direct connection between the support means and thebarrel (12) or the breech assembly (15).
 13. An elevating apparatus foran artillery gun of the type comprising a breech assembly (15) connectedto a barrel (12), the breech assembly (15) having a firing mechanism forfiring a projectile through an open end of the barrel (12), theelevating apparatus comprising a support means adapted to support thebarrel (12) and breech assembly (12), and an elevating mechanism forraising and lowering the barrel (12), wherein the elevating mechanismincludes a piston and cylinder (40) which are arranged such thatrelative movement between the piston and cylinder (40) causes the barrel(12) to be raised or lowered.
 14. Apparatus according to claim 13,wherein the piston and cylinder are secured to the support means. 15.Apparatus according to claim 13 or 14, wherein the support meansincludes a cradle (21) adapted to support the barrel (12) directly orindirectly, and at least one support member (22) secured at one end tothe cradle (21) and at the other end to a support platform, and whereinthe piston and cylinder (40) are secured to the cradle (21) so that theycan provide support for the barrel (12) and the breech assembly (15) 16.Apparatus according to chains 13, 14 or 15, wherein there are two ofsaid pistons and cylinders (40).
 17. Apparatus according to claim 15 and16, wherein a connecting member (33) is connected between the supportplatform (31) and each of said pistons and cylinders (40), and across-connecting member (36) is connected between said pistons and/orbetween each of said cylinders (40).
 18. Apparatus according to claim17, wherein the arrangement of the pistons and cylinders (40), theconnecting members (33) the cross-connecting member (36) and the or eachsupport member (22) is substantially tetrahedral.
 19. A traversingapparatus for an artillery gun comprising a breech assembly (15)connected to a barrel (12), the breech assembly (15) having a firingmechanism, for firing a projectile through an open end of the barrel(12), the traversing apparatus comprising: a support platform (31) whichis adapted to support the barrel and breech assembly in such a mannerthat said barrel (12) and breech assembly (15) may rotate relative tothe support platform (31) in order to impart a traversing motion to thebarrel and breach assembly, the support platform including an arcuateguide member having support means adapted to support the barrel (12) andbreech assembly (15) so that the support means follows the guide memberduring said traversing motion of the barrel (12) and breech assembly(15); and drive means secured to the support means and adapted to drivemovement of the support means along the guide member to cause saidtraversing motion, wherein the drive means comprises a drive wheel (38)and a drive cable (39) wrapped around the drive wheel or in connectiontherewith, the drive cable being substantially fixed relative to theguide member so that rotation of the drive wheel (38) causes the drivewheel (38) to be driven along the guide member.
 20. Apparatus accordingto claim 19, wherein the drive cable (39) sits in a recess provided inthe drive wheel (38).
 21. Apparatus according to claim 19, wherein therecess in the drive wheel (38) extends around the drive wheel (38) in asubstantially helical fashion.
 22. Apparatus according to claim 19 20 or21, wherein tensioning means is provided to maintain the drive cable(39) in tension.
 23. Apparatus according to claim 19, 20, 21 or 22,wherein the drive cable (39) extends at least partly around the guidemember
 24. Apparatus according to any one of claims 19 to 23, whereinthe support means includes at least one support member adapted tosupport the barrel (12) and the breech assembly (15).
 25. Apparatusaccording to claim 24, wherein the or each support member includes amechanism, for adjusting the elevation of the barrel (12).
 26. Apparatusaccording to any one of claims 19 to 25 wherein the guide member isprovided with a T-shaped recess, and the support means is provided witha formation adapted to engage the recess, thereby guiding movement ofthe support means along the guide member.
 27. An elevating apparatus foran artillery gun of the type comprising a breech assembly (15) connectedto a barrel (12), the breech assembly (15) having a firing mechanism forfiring a projectile through an open end of the barrel (12), theelevating apparatus comprising three base members (34, 36) disposed in asubstantially triangular arrangement, and three support members (22,40)arranged to support the artillery gun, wherein at least one of thesupport members (40) is extendible to vary the elevation of theartillery gun, and wherein the base members (34,36) and the supportmembers (22,40) are disposed in a substantially tetrahedral arrangement.28. An elevating apparatus according to claim 27, wherein two of thesupport members (40) are extendible.
 29. An elevating apparatusaccording to claim 27 or 28, wherein the or each extendible supportmember comprises a piston and cylinder arrangement.
 30. An artillery guncomprising a breech assembly (15) connected to a barrel (12), the breechassembly (15) having a firing mechanism for firing a projectile throughan open end of the barrel (12), and further comprising a recoilbuffering apparatus according to any one of claims 1 to 12, an elevatingapparatus according to any one of claims 13 to 18 or claims 27 to 29,and/or a traversing apparatus according to any one of claims 19 to 26.31. An artillery gun according to any one of the preceding claims,wherein the artillery gun is platform or vehicle mounted.
 32. Anartillery gun according to any one of the preceding claims, wherein theartillery gun is a mortar gun.
 33. An artillery gun according to claim30, wherein the artillery gun is a mortar gun, and wherein the barrel(12) includes a muzzle brake (11) through which projectile propellantgas can escape from the barrel (12).
 34. A mortar gun comprising abreech assembly (15) connected to a barrel (12), the breech assembly(15) having a firing mechanism for firing a projectile through an openend of the barrel (12), wherein the barrel (12) includes a muzzle brake(11) through which projectile propellant gas can escape from the barrel(12).
 35. A mortar gun according to claim 34, wherein the muzzle brake(11) is disposed adjacent the open end of the barrel (12).
 36. A mortargun according to claim 34 or 35, wherein the muzzle break (11) comprisesa plurality of apertures provided in the barrel (12).
 37. A mortar gunaccording to any one of claims 34 to 36, further comprising a recoilbuffering apparatus according to any one of claims 1 to 12, an elevatingapparatus according to any one of claims 13 to 18 or 27 to 29, and/or atraversing apparatus according to any one of claims 19 to 26.